U2628 GMC Code - Reductant Control Module Lost Communication With Reductant Concentration Sensor
Quick Answer
The U2628 diagnostic trouble code (DTC) for GMC vehicles indicates that there is a communication issue between the Reductant Control Module (RCM) and the Reductant Concentration Sensor (RCS) within the vehicle's Selective Catalytic Reduction (SCR) system. Common causes include Faulty Reductant Control Module: A malfunctioning RCM could be the root cause of the communication issue with the RCS, Defective Reductant Concentration Sensor: A faulty RCS may not be sending accurate data to the RCM, leading to communication errors, Wiring or Connection Issues: Corrosion, damage, or loose connections in the wiring harness between the RCM and RCS could prevent proper communication. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.
- What it means
- U2628 GMC indicates Reductant Control Module Lost Communication With Reductant Concentration Sensor.
- Common causes
- Common causes include Faulty Reductant Control Module: A malfunctioning RCM could be the root cause of the communication issue with the RCS, Defective Reductant Concentration Sensor: A faulty RCS may not be sending accurate data to the RCM, leading to communication errors, Wiring or Connection Issues: Corrosion, damage, or loose connections in the wiring harness between the RCM and RCS could prevent proper communication.
- Severity
- High - diagnose this code as soon as possible.
- Can I drive?
- Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.
Fix Your Car Smarter
Try the New AutoCodes App!
Get complete OBDII diagnostics, repair solutions, and cost estimates, plus AI chat support on demand.
Code U2628 GMC Description
The U2628 diagnostic trouble code (DTC) for GMC vehicles indicates that there is a communication issue between the Reductant Control Module (RCM) and the Reductant Concentration Sensor (RCS) within the vehicle's Selective Catalytic Reduction (SCR) system. The SCR system is responsible for reducing harmful emissions by injecting a urea-based solution (commonly known as diesel exhaust fluid or DEF) into the exhaust stream to convert harmful nitrogen oxides (NOx) into nitrogen and water vapor.
Common Causes of U2628 GMC
- Faulty Reductant Control Module: A malfunctioning RCM could be the root cause of the communication issue with the RCS.
- Defective Reductant Concentration Sensor: A faulty RCS may not be sending accurate data to the RCM, leading to communication errors.
- Wiring or Connection Issues: Corrosion, damage, or loose connections in the wiring harness between the RCM and RCS could prevent proper communication.
- Software or Firmware Errors: Issues with the software or firmware within the RCM could result in communication failures with the RCS.
- Environmental Factors: Harsh operating conditions or exposure to extreme temperatures could impact the communication between the RCM and RCS.
Symptoms of U2628 GMC
- Check Engine Light: The most common symptom associated with the U2628 code is the illumination of the Check Engine Light on the vehicle's dashboard.
- Reduced Fuel Efficiency: A decrease in fuel efficiency may be noticed due to the improper functioning of the SCR system.
- Poor Performance: The vehicle may experience reduced performance, including sluggish acceleration or rough idling.
- Failed Emissions Test: If the vehicle is subject to emissions testing, it may fail due to increased emissions output caused by the communication issue between the RCM and RCS.
How to Fix U2628 GMC
- Diagnose the Issue: Use a diagnostic scanner to retrieve the specific trouble code and pinpoint the source of the communication problem between the RCM and RCS.
- Inspect Wiring and Connections: Check the wiring harness and connections between the RCM and RCS for any damage, corrosion, or loose connections that may be causing the communication issue.
- Test Reductant Concentration Sensor: Test the RCS to ensure it is functioning properly and sending accurate data to the RCM.
- Replace Faulty Components: If the RCM or RCS is found to be faulty, replace the component with a new one to restore proper communication within the SCR system.
- Clear Codes and Test Drive: After completing the repairs, clear the diagnostic trouble codes, and test drive the vehicle to ensure the issue has been resolved.
Cost to Fix U2628 GMC
The typical repair costs for addressing a U2628 DTC can vary depending on the specific cause of the communication issue and the cost of parts and labor. On average, the cost for parts such as a new Reductant Control Module or Reductant Concentration Sensor can range from $200 to $500. Labor costs at an auto repair shop can range from $80 to $150 per hour, with the total repair time varying based on the complexity of the issue.
Need more information about the U2628 GMC code?
Need more information on how to fix the U2628 GMC code? Get Access to Factory Service Manuals
Need Help with the Code?
Get the U2628 GMC code diagnosed by a professional: Find a repair shop in your area
Frequently Asked Questions about U2628 GMC Code
1. What are the common symptoms of OBDII code U2628 in a GMC vehicle?
The common symptoms of code U2628 include the check engine light turning on, reduced engine performance, and potential issues with the vehicle's emissions system.
2. What does the OBDII code U2628 "Reductant Control Module Lost Communication With Reductant Concentration Sensor" mean for a GMC vehicle?
This code indicates a communication problem between the reductant control module and the reductant concentration sensor in the vehicle's emissions system.
3. What are the possible causes of OBDII code U2628 in a GMC vehicle?
Some possible causes of this code include faulty wiring or connections between the control module and sensor, a malfunctioning sensor, or issues with the control module itself.
4. How can I diagnose the OBDII code U2628 in my GMC vehicle?
Diagnosing this code typically involves using a diagnostic scanner to retrieve the specific fault codes, checking the wiring and connections between the control module and sensor, and testing the sensor for proper functionality.
5. What are some repair tips for addressing OBDII code U2628 in a GMC vehicle?
Repairing this code may involve repairing or replacing damaged wiring or connectors, replacing the reductant concentration sensor if faulty, or reprogramming the control module if needed.
6. Can I drive my GMC vehicle with OBDII code U2628 present?
It is generally not recommended to drive the vehicle with this code present, as it can lead to reduced engine performance and potential issues with the emissions system.
7. Is it possible to reset the OBDII code U2628 in a GMC vehicle without fixing the underlying issue?
While it is possible to clear the code temporarily, it will likely return if the root cause of the communication problem between the control module and sensor is not addressed.
8. How much does it cost to repair OBDII code U2628 in a GMC vehicle?
The cost of repairing this code can vary depending on the specific cause of the issue, the extent of the repairs needed, and whether any parts need to be replaced. It is recommended to consult with a mechanic for an accurate estimate.
9. Is OBDII code U2628 a common issue in GMC vehicles?
While not as common as some other OBDII codes, U2628 can occur in GMC vehicles, particularly in models equipped with reductant control systems for emissions compliance.
10. Can I prevent OBDII code U2628 from appearing in my GMC vehicle?
Regular maintenance, such as checking and maintaining the emissions system components, keeping up with scheduled inspections, and addressing any warning lights promptly, can help prevent this code from appearing.
Discuss the causes and fixes for U2628 GMC OBDII Code
Code U2628 GMC comments
No comments found for this page.
Fix Your Car Smarter
Try the New AutoCodes App!
Get complete OBDII diagnostics, repair solutions, and cost estimates, plus AI chat support on demand.